Gasket with embedded capacitive sensor

ABSTRACT

An electronic device is disclosed. In some examples, the device includes one or more force sensors at its perimeter. The force sensors can be included in a gasket further comprising a rubber-like gasket cover and a compressible dielectric such as air or silicone, for example. A plurality of conductive plates can be embedded in the gasket cover with routing traces coupled thereto to sense a capacitance between the conductive plates. The gasket, including the one or more capacitive sensors, can be disposed between a cover glass and a lower housing of the electronic device. The capacitance of the one or more sensors can change in response to an applied force at the cover glass of the device. The change in capacitance can be sensed via the routing traces to measure the magnitude and, in some examples, location of the applied force.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/272,105 (now U.S. Publication No. 2018-0081485), filed Sep. 21, 2016,the entire disclosures of which are incorporated herein by reference forall purposes.

FIELD OF THE DISCLOSURE

This relates to a capacitive sensor included in an electronic deviceand, more particularly, to a capacitive sensor embedded in a gasketconfigured for detecting a force at the electronic device.

BACKGROUND OF THE DISCLOSURE

Many types of input devices are presently available for performingoperations in a computing system, such as buttons or keys, mice,trackballs, joysticks, touch electrode panels, touch screens and thelike. Touch screens, in particular, are becoming increasingly popularbecause of their ease and versatility of operation as well as theirdeclining price. Touch screens can include a touch electrode panel,which can be a clear panel with a touch-sensitive surface, and a displaydevice such as a liquid crystal display (LCD) that can be positionedpartially or fully behind the panel so that the touch-sensitive surfacecan cover at least a portion of the viewable area of the display device.Touch screens can allow a user to perform various functions by touchingthe touch electrode panel using a finger, stylus or other object at alocation often dictated by a user interface (UI) being displayed by thedisplay device. In general, touch screens can recognize a touch and theposition of the touch on the touch electrode panel, and the computingsystem can then interpret the touch in accordance with the displayappearing at the time of the touch, and thereafter can perform one ormore actions based on the touch. In the case of some touch sensingsystems, a physical touch on the display is not needed to detect atouch. For example, in some capacitive-type touch sensing systems,fringing electrical fields used to detect touch can extend beyond thesurface of the display, and objects approaching near the surface may bedetected near the surface without actually touching the surface.

In some examples, touch panels/touch screens may include force sensingcapabilities—that is, they may be able to detect an amount of force withwhich an object is touching the touch panels/touch screens. These forcescan constitute force inputs to electronic devices for performing variousfunctions, for example. In some examples, an electronic device caninclude one or more force sensors around the perimeter of a touchscreen.

SUMMARY

The present disclosure relates to a dielectric-filled gasket with acapacitive sensor. In some examples, the gasket can be included in anelectronic device further comprising a cover glass and a lower housing.The cover glass can be attached to the lower housing via a clampmechanism, for example. In some examples, the lower housing can includea groove around its interior perimeter in which the gasket can sit,forming a seal. The gasket can include one or more pairs of parallelconductive plates encased in a rubber-like material, the rubber-likematerial surrounding a dielectric such as air or silicone, for example.In some examples, the gasket can further include routing traces coupledto the parallel conductive plates to sense a change in capacitancecaused by a force applied to the cover glass of the device. A pair ofconductive plates can be used to determine a magnitude of an appliedforce, for example. In some examples, the gasket can include multiplepairs of parallel conductive plates so as to determine a location of anapplied force in addition to its magnitude (e.g., one sensor paircorresponding to each corner of a device).

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate exemplary devices that can include one or moreforce sensors according to examples of the disclosure.

FIG. 2A illustrates a top view of an exemplary device including a forcesensor at its perimeter according to examples of the disclosure.

FIG. 2B illustrates a cross-section of a device including a force sensoraccording to examples of the disclosure.

FIG. 3A illustrates a top view of an exemplary device including aplurality force sensors, each including conductive plates, at itsperimeter according to examples of the disclosure.

FIG. 3B illustrates a cross-section of a device including a force sensoraccording to examples of the disclosure.

FIG. 4A illustrates a top view of an exemplary device including a forcesensor at its perimeter according to examples of the disclosure.

FIGS. 4B-4C illustrate cross-sectional views of an exemplary deviceincluding a force sensor according to examples of the disclosure.

FIG. 5 illustrates an exemplary method for measuring an applied force atan electronic device according to examples of the disclosure.

FIG. 6 illustrates exemplary computing system capable of implementingforce sensing according to examples of the disclosure.

DETAILED DESCRIPTION

In the following description of examples, reference is made to theaccompanying drawings which form a part hereof, and in which it is shownby way of illustration specific examples that can be practiced. It is tobe understood that other examples can be used and structural changes canbe made without departing from the scope of the disclosed examples.

The present disclosure relates to a dielectric-filled gasket with acapacitive sensor. In some examples, the gasket can be included in anelectronic device further comprising a cover glass and a lower housing.The cover glass can be attached to the lower housing via a clampmechanism, for example. In some examples, the lower housing can includea groove around its interior perimeter in which the gasket can sit,forming a seal. The gasket can include one or more pairs of parallelconductive plates encased in a rubber-like material, the rubber-likematerial surrounding a dielectric such as air or silicone, for example.In some examples, the gasket can further include routing traces coupledto the parallel conductive plates to sense a change in capacitancecaused by a force applied to the cover glass of the device. A pair ofconductive plates can be used to determine a magnitude of an appliedforce, for example. In some examples, the gasket can include multiplepairs of parallel conductive plates so as to determine a location of anapplied force in addition to its magnitude (e.g., one sensor paircorresponding to each corner of a device).

FIGS. 1A-1C illustrate exemplary devices that can include one or moreforce sensors according to examples of the disclosure. FIG. 1Aillustrates an example mobile telephone 136 that includes a touch screen124. FIG. 1B illustrates an example digital media player 140 thatincludes a touch screen 126. FIG. 1C illustrates an example watch 144that includes a touch screen 128. It is understood that the above touchscreens can be implemented in other devices as well, such as tabletcomputers or other wearable devices. Further, though the examples of thedisclosure are provided in the context of a touch screen, it isunderstood that the examples of the disclosure can similarly beimplemented in a touch sensor panel without display functionality.

In some examples, touch screens 124, 126 and 128 can be based onself-capacitance. A self-capacitance based touch system can include amatrix of small, individual plates of conductive material that can bereferred to as touch node electrodes. For example, a touch screen caninclude a plurality of individual touch node electrodes, each touch nodeelectrode identifying or representing a unique location on the touchscreen at which touch or proximity (i.e., a touch or proximity event) isto be sensed, and each touch node electrode being electrically isolatedfrom the other touch node electrodes in the touch screen. Such a touchscreen can be referred to as a pixelated self-capacitance touch screen,though it is understood that in some examples, the touch node electrodeson the touch screen can be used to perform scans other thanself-capacitance scans on the touch screen (e.g., mutual capacitancescans). During operation, a touch node electrode can be stimulated withan AC waveform, and the self-capacitance to ground of the touch nodeelectrode can be measured. As an object approaches the touch nodeelectrode, the self-capacitance to ground of the touch node electrodecan change. This change in the self-capacitance of the touch nodeelectrode can be detected and measured by the touch sensing system todetermine the positions of multiple objects when they touch, or come inproximity to, the touch screen. In some examples, the electrodes of aself-capacitance based touch system can be formed from rows and columnsof conductive material, and changes in the self-capacitance to ground ofthe rows and columns can be detected, similar to above. In someexamples, a touch screen can be multi-touch, single touch, projectionscan, full-imaging multi-touch, capacitive touch, etc.

In some examples, touch screens 124, 126 and 128 can be based on mutualcapacitance. A mutual capacitance based touch system can include driveand sense lines that may cross over each other on different layers, ormay be adjacent to each other on the same layer. The crossing oradjacent locations can be referred to as touch nodes. During operation,the drive line can be stimulated with an AC waveform and the mutualcapacitance of the touch node can be measured. As an object approachesthe touch node, the mutual capacitance of the touch node can change.This change in the mutual capacitance of the touch node can be detectedand measured by the touch sensing system to determine the positions ofmultiple objects when they touch, or come in proximity to, the touchscreen.

In some examples, a device of the disclosure can include force sensingcapability in addition to the touch sensing capability discussed above.In the context of this disclosure, touch sensing can refer to the touchscreen's ability to determine the existence and/or location of an objecttouching the touch screen, and force sensing can refer to the touchscreen's ability to determine a “depth” of the touch on the touch screen(e.g., the degree of force with which the object is touching the touchscreen). In some examples, the touch screen can also determine alocation of the force on the touch screen.

FIG. 2A illustrates a top view of an exemplary device 200 including aforce sensor 210 at its perimeter according to examples of thedisclosure. In some examples, the force sensor 210 can be one continuoussensor around the perimeter of the device 200. The force sensor 210 caninclude a connection 212 that can be operatively coupled to a processor(not shown) of the device 200, for example. In some examples, the forcesensor 210 can include multiple force sensors electrically isolated fromeach other, wherein each force sensor has a connection operativelycoupled to the processor. A cross-section of device 200 is illustratedin FIG. 2B.

FIG. 2B illustrates a cross-section of a device 200 including a forcesensor 210 according to examples of the disclosure. In some examples,the device 200 can include a cover glass 250 (which can alternativelymade of other materials such as plastic), a device housing 260, and aforce sensor 210 disposed therebetween. The force sensor 210 can includepressure-sensitive adhesive (PSA) 214, conductive plates 216,connections 212, and a compressible dielectric 218. In some examples,the conductive plates 216 can be disposed at a distance d1 from oneanother and each can be coupled to a connection 212. Conductive plates216 can be situated normal to an applied force at the cover glass 250 ofdevice 200. Additionally or alternatively, in some examples, conductiveplates 216 can be situated in a different orientation to sense anapplied force at a different location (e.g. a force applied at the edgesof device 200).

In some examples, conductive plates 216 can function as a parallel-platecapacitor. When no force is applied to the cover glass 250 of the device200, the conductive plates can be a nominal distance d1 from each other.When a force is applied to cover glass 250, the distance d1 between theconductive plates 216 can change. In some examples, a change in distanced1 between the conductive plates 216 can cause the capacitance of theplates to change. The capacitance of the conductive plates 216 can bemeasured via connections 212, for example. In some examples, thecapacitance can be measured by applying a first signal (e.g., an ACsignal) to one of the conductive plates 214 and measuring a secondsignal at the other conductive plate. In some examples, the PSA 214 andcompressible dielectric 218 can be made of compressible materials thatyield under an applied force, allowing for distance d1 to change inresponse to an applied force. Therefore, by sampling, via connections212, the capacitance of pressure sensor 210, a magnitude of force at thecover glass 250 can be determined.

In some examples, a location of an applied force can be determined basedon touch data provided by a touch sensor, such as a touch screen (e.g.,touch screen 124, 126, or 128) further included in device 200. In someexamples, multiple force sensors 210 can be included along the perimeterof device 200. By determining the magnitude of force sensed by each of aplurality of force sensors, a centroid of one or more applied forces canbe determined.

In some examples, the cover glass 250 and device housing 260 can be heldtogether by PSA 214 included in the force sensor 210. By including aforce sensor 210 around the perimeter of device 200, the PSA 214 canprotect the internal electronics (not shown) of the device from liquidsand particles outside of the device.

Although the exemplary force sensor 210 described with reference toFIGS. 2A-2B can measure force and provide PSA 214 to hold device 200together, over time, the PSA can weaken from exposure to chemicalsand/or sheer forces. Eventually, device 200 can lose its waterproofproperties or cover glass 250 can be come displaced as PSA 214 weakens.Further, to access the internal electronics (not shown) of device 200for troubleshooting or maintenance purposes, the cover glass 250 must beremoved, which can destroy the pressure sensor 210. Therefore,installation of a new pressure sensor can be required in addition to anyother maintenance to be performed on the device. Therefore, in someexamples, it can be advantageous to hold the device 200 together withoutthe use of PSA and include a pressure sensor that can function as agasket to seal the inside of the device.

FIG. 3A illustrates a top view of an exemplary device 300 including aplurality force sensors, each including conductive plates 316, at itsperimeter according to examples of the disclosure. In some examples, theconductive plates 316 can be included in a gasket, which can furtherinclude gasket cover 314, disposed along the perimeter of the device300. Gasket cover 314 can be made of a flexible and/or compressiblematerial, such as rubber or plastic, for example. In some examples, eachconductive plate 316 can be coupled to a connection 312 that can befurther operatively coupled to a processor of the device 300. The gasketincluding the conductive plates 316 can seal the perimeter of the device300, for example. In some examples, the conductive plates 314 can beelectrically isolated from one another by gaps 311. The gaps 311 can befilled with the gasket cover 314 material, thereby forming a completegasket around the perimeter of the device 300. Therefore, in someexamples, the gasket can be rectangle-shaped to conform to the shape ofthe device 300. Other shapes, such as circles, ovals, or squares, forexample, are possible. In some examples, a different material can beused to fill gaps 311. Alternatively, in some examples, the device 300can include one force sensor along its full perimeter. Device 300 canfurther include a channel 362 to hold the gasket including theconductive plates 316 in place, for example. In some examples, thechannel 362 can include gaps 364 to allow the connections 312 to becoupled to internal electronics of the device 300. Although FIG. 3Aillustrates the conductive plates 316 as being placed at the corners ofdevice 300, in some examples, different placement of the conductiveplates 316 is possible. Furthermore, although device 300 can have fourpairs of conductive plates 316; other numbers of conductive plates arepossible. A cross-section of device 300 is illustrated in FIG. 3B.

FIG. 3B illustrates a cross-section of a device 300 including a forcesensor 310 according to examples of the disclosure. In some examples,force sensor 310 can be one of a plurality of force sensors included indevice 300. The device 300 can include a cover glass 350 (or other covermaterial), a device housing 360, and a force sensor 310 disposedtherebetween, for example. The device 300 can be held together by clamp370, which can apply a nominal compressive force represented by spring372. Clamp 370 can include a spring like mechanism other than spring 372in some examples. The force sensor 310 can include gasket cover 314(e.g., a rubber-like insulative coating), conductive plates 316,connections 312, and a compressible dielectric 318. In some examples,the conductive plates 316 can be disposed at a distance d2 from oneanother and each be coupled to a connection 312. Conductive plates 316can be situated normal to an applied force at the cover glass 350 ofdevice 300. Additionally or alternatively, in some examples, conductiveplates 316 can be situated in a different orientation to sense anapplied force at a different location (e.g. a force applied at the edgesof device 300).

In some examples, the gasket including the force sensors 310 can bemanufactured using an over-molding technique. One or more sensors 310including conductive plates 316, compressible dielectric 318, andconnections 312 can be provided. The one or more sensors 310 can bearranged in a shape of the perimeter of device 300, and the gasket cover314 can be over-molded to cover the one or more sensors. In someexamples, the gasket can include a single force sensor 310 formed in theshape of the perimeter of device 300. Over-molding can include providingsensors 310 in a mold having the shape of the gasket and filling themold with the gasket cover 314 material, thus applying the gasket coveraround the sensors, for example. Additionally or alternatively, thegasket cover 314 material can be applied to the arranged sensors 310with a different technique, such as dipping the sensors in the gasketcover material or brushing or spraying the gasket material onto thesensors. Once formed, the gasket can be inserted into the channel 362 ofthe device housing 360 and the rest of the device 300 can be assembled.In some examples, the resulting cross-section of the gasket can have anoval shape. Depending on how the gasket cover material is applied, othercross-sectional shapes, such as circles, squares, or rectangles, forexample, are possible.

Once the device 300 is assembled with the force sensors 310 in thecorrect position, conductive plates 316 can function as a parallel-platecapacitor. When no force is applied to the cover glass 350 of the device300, the conductive plates can be a nominal distance d2 from each other.A capacitance of the conductive plates 316 can be measured viaconnections 312. In some examples, a capacitance can be measured byapplying a first signal to one of the conductive plates 316 andmeasuring a second signal at the other conductive plate. In someexamples, the gasket cover 314 and compressible dielectric 318 can bemade of compressible materials that yield under an applied force. Thegasket cover 314 and compressible dielectric 318 can be made of a samematerial or of different materials. When a force is applied to coverglass 350, the distance d2 between the conductive plates 316 can change.In some examples, a change in distance d2 between the conductive plates316 can cause the capacitance of the plates to change. Therefore, bysampling the capacitance of pressure sensor 310 via connections 312, amagnitude of force at the cover glass 350 can be determined. In someexamples, it can be advantageous to include a flexible, but notcompressible gasket cover 314 and a compressible dielectric 318 toincrease a change in distance d2 between conductive plates 316 inresponse to an applied force.

In some examples, a location of one or more applied forces can bedetermined based on the relative forces measured at each of theplurality of force sensors 310. Additionally or alternatively, touchdata provided by a touch sensor, such as a touch screen (e.g., touchscreen 124, 126, or 128) further included in device 300 can be used todetermine the location of the one or more applied forces.

In some examples, the cover glass 350 and device housing 360 can be heldtogether by clamp 370. Clamp 370 can include a spring 372 (or othersimilar mechanism) to apply a nominal compressive force between thecover glass 350 and the device housing 360. It should be understood thatclamp 370 is exemplary and other coupling means may be used. Forexample, a clamp can be interior to the device and/or may include adifferent mechanism to apply a nominal compressive force to join coverglass 350 and device housing 360. Spring 372 and compressible dielectric318 can be selected such that the nominal force required to hold device300 together can be overcome by a force applied by a user of the device.When selecting compressible dielectric 318, a tradeoff can be madebetween providing a low nominal force and increased responsiveness witha soft dielectric versus increased durability with a firm dielectric.Because clamp 370 can apply a nominal force, a minimum measurable forcecan be limited by the clamp. That is, forces that are a lower magnitudethan the nominal force may not be sensed. In some examples, a maximummeasurable force can be limited by a height of channel 362. This maximummeasurable force can simplify calibration by providing an upper limit ona measurable applied force. Further, channel 362 can limit thedisplacement of cover glass 350, protecting the internal electronics ofdevice 300. Channel 362 can hold the gasket including the sensor 310 inplace. By including the gasket, including sensors 310, around the fullperimeter of device 300, the gasket can provide a seal to protect theinternal electronics (not shown) of the device from liquids andparticles outside of the device.

By providing the clamp 370 to hold device 300 together and the gasketincluding pressure sensors 310 as a seal, the device can have increaseddurability compared to a device (e.g., device 200) held together by PSA(e.g., PSA 214). For example, device 300 can be chemically resistant.Furthermore, the pressure sensors 310 can be reused if cover glass 350is removed to perform troubleshooting or maintenance on the internalelectronics of the device 300. To access the internal electronics of thedevice 300, clamp 370 and cover glass 350 can be removed. To reassemblethe device, clamp 370 and cover glass 350 can be reassembled withoutdamaging sensor 310. In some examples, after reassembly, sensor 310 canbe recalibrated to account for any change in the nominal force appliedby the clamp 370.

FIG. 4A illustrates a top view of an exemplary device 400 including aforce sensor 410 at its perimeter according to examples of thedisclosure. In some examples, the force sensor 410 can be disposed alongthe perimeter of the device 400. The force sensor 410 can include aconnection 412 that can be operatively coupled to a processor of thedevice 400, for example. The force sensor 410 can function as a gasketto seal the perimeter of the device 400, for example. Therefore, in someexamples, the gasket can be rectangle-shaped to conform to the shape ofthe device 400. In some examples, other shapes, such as squares,circles, or ovals, for examples, are possible. Device 400 can furtherinclude a channel 462 to hold the gasket including the pressure sensor410 in place, for example. In some examples, the channel 462 can includea gap 464 to allow the connection 412 to be coupled to internalelectronics of the device 300. Although device 400 is shown as includinga single force sensor 410 along its perimeter, in some examples,multiple electrically isolated force sensors, each with connectionscouplable to a processor, are possible. Cross-sectional views of device400 are illustrated in FIGS. 4B-4C.

FIGS. 4B-4C illustrate cross-sectional views of an exemplary device 400including a force sensor 410 according to examples of the disclosure. Insome examples, force sensor 410 can be one of a plurality of forcesensors included in device 400. The device 400 can include a cover glass450 (or other cover material), a device housing 460, and a force sensor410 disposed therebetween, for example. The device 400 can be heldtogether by a clamp 470 configured to apply a nominal compressive forceto the device. In some examples, this compressive force can be modeledby a spring 472. The force sensor 410 can include gasket cover 414,conductive plates 416, connections 412, and a compressible dielectric418. The compressible dielectric 418 can be non-structural, for example.In some examples, air can be used as the compressible dielectric 418,thus allowing for a hollow gasket. Conductive plates 416 can be situatednormal to an applied force at the cover glass 450 of device 400.Additionally or alternatively, in some examples, conductive plates 416can be situated in a different orientation to sense an applied force ata different location (e.g. a force applied at the edges of device 400).

In some examples, the gasket can be manufactured using an extrusiontechnique. One or more extrusion molds can be provided to shape theconductive plates 416, flexible dielectric 418, and gasket cover 414into an elongated shape with a desired cross-sectional structure.Although the cross section of the gasket illustrated in FIG. 4B can beoval-shaped, other cross-sectional shapes, such as squares, rectangles,or circles, for example, are possible, depending on the shape of theextrusion molds used. The resulting elongated capacitor can be shaped tofit the perimeter of device 400, thus forming the gasket including thepressure sensor 410, as described above. Extrusion molding can allow thegasket to be formed using a non-structural dielectric, for example. Forexample, extrusion molding can be used to form a hollow gasket, allowingair to function as the compressible dielectric 418. Once formed, thegasket can be inserted into the channel 462 of the device housing 460and the rest of the device 400 can be assembled.

Once the device 400 is assembled, including the pressure sensor 410,conductive plates 416 can function as a parallel-plate capacitor. Theconductive plates 416 can be disposed such that, when no force ispresent, their centers are a distance d3 from each other and their edgesare a distance d4 from each other, due to their curvature, as shown inFIG. 4B. In the presence of a force F, the conductive plates can movecloser together and their curvature can decrease. For example, thecenters of the conductive plates 416 can be a distance d5 from eachother and the edges can be a distance d6 from each other, as shown inFIG. 4C. In some examples, these changes in distance between theconductive plates 416 can cause a capacitance of the plates to change.The capacitance of the conductive plates 416 can be measured viaconnections 412, for example. In some examples, a capacitance can bemeasured by applying a first signal to one of the conductive plates 416and measuring a second signal at the other conductive plate. In someexamples, the gasket cover 414 and compressible dielectric 418 can bemade of compressible materials that yield under an applied force. Insome examples, air can be used as the compressible dielectric 418,allowing the gasket to be hollow. Therefore, by sampling the capacitanceof pressure sensor 410 via connections 412, a magnitude of force at thecover glass 450 can be determined.

In some examples, a location of one or more applied forces can bedetermined based on touch data provided by a touch sensor, such as atouch screen (e.g., touch screen 124, 126 or 128) further included indevice 400. That is, it can be assumed that a centroid of touch is alsoa centroid of an applied force, for example. In some examples includingmultiple pressure sensors, the relative forces measured at each of theplurality of force sensors can be weighed to determine force location inaddition to or as an alternative to using touch data to determine forcelocation.

In some examples, the cover glass 450 and device housing 360 can be heldtogether by a clamp 470. Clamp 470 can include a spring 472 (or similarmechanism) to apply a nominal compressive force between the cover glass450 and the device housing 460. It should be understood that clamp 470is exemplary and other coupling means may be used. For example, a clampor other coupling means can be interior to the device and/or may includea different mechanism to apply a nominal compressive force to join coverglass 450 and device housing 460. Spring 472 and compressible dielectric418 can be selected such that the nominal force required to hold device400 together can be readily overcome by a force applied by a user of thedevice. When selecting compressible dielectric 418, a tradeoff can bemade between providing a low nominal force and increased responsivenessby using a soft dielectric versus increased durability provided by usinga firm dielectric. In some examples, it can be advantageous to use airor another non-structural dielectric material as the compressibledielectric 418 because it is both soft and robust. For example, air canbe repeatedly compressed by applied forces over time without deformingor otherwise deteriorating. Because clamp 470 can apply a nominalcompressive force, a minimum detectable force can be set by the clamp.That is, an applied force with a magnitude less than the nominalcompressive force may not be sensed. In some examples, a maximummeasurable force can be limited by a height of channel 462. This maximummeasurable force can simplify calibration by providing an upper limit ona measurable applied force. Further, channel 462 can limit thedisplacement of cover glass 450, protecting the internal electronics ofdevice 400. Channel 462 can hold the gasket including the sensor 410 inplace. By including the gasket around the full perimeter of device 400,the gasket can provide a seal to protect the internal electronics (notshown) of the device from liquids and particles outside of the device.

By providing the clamp 470 to hold device 400 together and the gasketincluding pressure sensors 410 as a seal, the device can have increaseddurability compared to a device (e.g., device 200) held together by PSA(e.g., PSA 214). For example, device 400 can be chemically resistant.Furthermore, the pressure sensors 410 can be reused if cover glass 450is removed to perform maintenance or troubleshooting on the internalelectronics of the device 400. To access the internal electronics of thedevice 400, clamp 470 and cover glass 450 can be removed. To re-assemblethe device, clamp 470 and cover glass 450 can be re-assembled withoutdamaging sensor 410. In some examples, after re-assembly, sensor 410 canbe recalibrated to account for any change in nominal force applied byclamp 470. Further, in some examples, air or a different non-structuraldialectic material can be used as compressible dielectric 418. In someexamples, air can be both soft and robust, allowing for a low nominalforce, relatively increased force sensor 410 responsiveness, and sensordurability, as described above.

FIG. 5 illustrates an exemplary method 500 for measuring an appliedforce at an electronic device according to examples of the disclosure.Method 500 can be performed by an electronic device according to theexampled described above with reference to FIGS. 1-4.

In some examples, the method 500 can include calibrating 502 the one ormore force sensors (e.g., force sensors 210, 310 or 410) included in theelectronic device. Calibration can be performed at the manufacturingfacility and/or using specialized equipment. For example, a series offorces of known magnitudes and locations can be applied to theelectronic device. The corresponding capacitive response of the one ormore force sensors can be measured and associated with the known appliedforce to create a model of the one or more force sensors. The model canbe a lookup table (LUT) or a function, for example, and can be stored ina memory of the electronic device.

While the device is operating, the one or more force sensors (e.g.,force sensors 210, 310 or 410) can be measured 504. In some examples,measuring a force sensor can include measuring a capacitance of a forcesensor including conductive plates (e.g., conductive plates 216, 316 or416). For example, the one or more force sensors can include twoconductive plates, forming a parallel plate capacitor. To measure thecapacitance of a force sensor including a parallel plate capacitor, afirst conductive plate can receive a first signal and a second signal ofa second plate can be measured (e.g., via connections 212, 312 or 412).The capacitance can be determined based on the measured signal of thesecond plate. In some examples, the one or more sensors can have adifferent number of conductive plates. Other types of force sensors arepossible.

In some examples, a magnitude of an applied force can be determined 506based on the measurement of the force sensor. In some examples,determining the magnitude of the applied force can include applying amodel (e.g., a LUT or a function) to the one or more measured forcesensors. The model can be obtained during a calibration procedure, suchas calibration 502, for example. In some examples, determining amagnitude of force can include combining the measurements from aplurality of force sensors included in a device (e.g., plurality offorce sensors 310 included in device 300).

In some examples, a location of force can also be determined 508.Determining a location of force can occur before, after, or at a sametime as determining a magnitude of applied force. In some examples,determining a location of force can include weighing the measurements ofa plurality of force sensors (e.g., plurality of force sensors 310),each at a unique location on the electronic device. Additionally oralternatively, determining a location of force can include analyzingtouch data from a touch sensor further included in the electronicdevice. For example, in a device including only one force sensor (e.g.,device 200 or 400, having sensor 210 or 410, respectively), the locationof force can be a location of an object touching the touch screen of adevice. In some examples, touch data can be used in conjunction withforce data from a plurality of force sensors for a more accuratedetermination of a force location.

In response to a detected force, the electronic device can perform 510an associated action. For example, the applied force can be user inputfor a secondary touch action (e.g., right click). In some examples, anaction to be performed in response to an applied force can varydepending on which application is running on the electronic device. Anapplied force can be processed as user input along with other inputmodalities such as touch screen input, keyboard input, and/or voicecontrol, to name a few examples.

FIG. 6 illustrates exemplary computing system 600 capable ofimplementing force sensing according to examples of the disclosure.Computing system 600 can include a touch sensor panel 602 to detecttouch or proximity (e.g., hover) events from a finger 606 or stylus 608at a device, such as a mobile phone, tablet, touchpad, portable ordesktop computer, portable media player, wearable device or the like.Touch sensor panel 602 can include a pattern of electrodes to implementvarious touch and/or stylus sensing scans. The pattern of electrodes canbe formed of a transparent conductive medium such as Indium Tin Oxide(ITO) or Antimony Tin Oxide (ATO), although other transparent andnon-transparent materials, such as copper, can also be used. Forexample, the touch sensor panel 602 can include an array of touch nodesthat can be formed by a two-layer electrode structure (e.g., row andcolumn electrodes) separated by a dielectric material, although in otherexamples the electrodes can be formed on the same layer. Touch sensorpanel 602 can be based on self-capacitance or mutual capacitance orboth, as previously described.

In addition to touch sensor panel 602, computing system 600 can includedisplay 604 and force sensor circuitry 610 (e.g., including force sensor210, 310 or 410) to create a touch and force sensitive display screen.Display 604 can use liquid crystal display (LCD) technology, lightemitting polymer display (LPD) technology, organic LED (OLED)technology, or organic electro luminescence (OEL) technology, althoughother display technologies can be used in other examples. In someexamples, the touch sensor panel 602, display 604 and/or force sensorcircuitry 610 can be stacked on top of one another. For example, touchsensor panel 602 can cover a portion or substantially all of a surfaceof display 604. In other examples, the touch sensor panel 602, display604 and/or force sensor circuitry 610 can be partially or whollyintegrated with one another (e.g., share electronic components, such asin an in-cell touch screen).

Computing system 600 can include one or more processors, which canexecute software or firmware implementing and synchronizing displayfunctions and various touch, stylus and/or force sensing functionsaccording to examples of the disclosure. The one or more processors caninclude a touch processor in touch controller 612, a force processor inforce controller 614 and a host processor 616. Force controller 614 canimplement force sensing operations, for example, by controlling forcesensor circuitry 610 (e.g., stimulating one or more electrodes of theforce sensor circuitry 610) and receiving force sensing data (e.g.,mutual capacitance information) from the force sensor circuitry 610(e.g., from one or more electrodes mounted on a flex circuit). In someexamples, the force controller 614 can implement the force sensing,error metric tracking and/or coefficient learning processes of thedisclosure. In some examples, the force controller 614 can be coupled tothe touch controller 612 (e.g., via an I2C bus) such that the touchcontroller can configure the force controller 614 and receive the forceinformation from the force controller 614. The force controller 614 caninclude the force processor and can also include other peripherals (notshown) such as random access memory (RAM) or other types of memory orstorage. In some examples, the force controller 614 can be implementedas a single application specific integrated circuit (ASIC) including theforce processor and peripherals, though in other examples, the forcecontroller can be divided into separate circuits.

Touch controller 612 can include the touch processor and can alsoinclude peripherals (not shown) such as random access memory (RAM) orother types of memory or storage, watchdog timers and the like.Additionally, touch controller 612 can include circuitry to drive (e.g.,analog or digital scan logic) and sense (e.g., sense channels) the touchsensor panel 602, which in some examples can be configurable based onthe scan event to be executed (e.g., mutual capacitance row-column scan,row self-capacitance scan, stylus scan, pixelated self-capacitance scan,etc.). The touch controller 612 can also include one or more scan plans(e.g., stored in memory) that can define a sequence of scan events to beperformed at the touch sensor panel 602. In one example, during a mutualcapacitance scan, drive circuitry can be coupled to each of the drivelines on the touch sensor panel 602 to stimulate the drive lines, andthe sense circuitry can be coupled to each of the sense lines on thetouch sensor panel to detect changes in capacitance at the touch nodes.The drive circuitry can be configured to generate stimulation signals tostimulate the touch sensor panel one drive line at a time, or togenerate multiple stimulation signals at various frequencies, amplitudesand/or phases that can be simultaneously applied to drive lines of touchsensor panel 602 (i.e., multi-stimulation scanning). In some examples,the touch controller 612 can be implemented as a single applicationspecific integrated circuit (ASIC) including the touch processor, driveand sense circuitry, and peripherals, though in other examples, thetouch controller can be divided into separate circuits. The touchcontroller 612 can also include a spectral analyzer to determine lownoise frequencies for touch and stylus scanning. The spectral analyzercan perform spectral analysis on the scan results from an unstimulatedtouch sensor panel 602.

Host processor 616 can receive outputs (e.g., touch information) fromtouch controller 612 and can perform actions based on the outputs thatcan include, but are not limited to, moving one or more objects such asa cursor or pointer, scrolling or panning, adjusting control settings,opening a file or a document, viewing a menu, making a selection,executing instructions, operating a peripheral device coupled to thehost device, answering a telephone call, placing a telephone call,terminating a telephone call, changing the volume or audio settings,storing information related to telephone communications such asaddresses, frequently dialed numbers, received calls, missed calls,logging onto a computer or a computer network, permitting authorizedindividuals access to restricted areas of the computer or computernetwork, loading a user profile associated with a user's preferredarrangement of the computer desktop, permitting access to web content,launching a particular program, encrypting or decoding a message, or thelike. Host processor 616 can receive outputs (e.g., force information)from force controller 614 and can perform actions based on the outputsthat can include previewing the content of a user interface element onwhich the force has been provided, providing shortcuts into a userinterface element on which the force has been provided, or the like.Host processor 616 can execute software or firmware implementing andsynchronizing display functions and various touch, stylus and/or forcesensing functions. Host processor 616 can also perform additionalfunctions that may not be related to touch sensor panel processing, andcan be coupled to program storage and display 604 for providing a userinterface (UI) to a user of the device. Display 604 together with touchsensor panel 602, when located partially or entirely under the touchsensor panel 602, can form a touch screen. The computing system 600 canprocess the outputs from the touch sensor panel 602 to perform actionsbased on detected touch or hover events and the displayed graphical userinterface on the touch screen.

Computing system 600 can also include a display controller 618. Thedisplay controller 618 can include hardware to process one or more stillimages and/or one or more video sequences for display on display 604.The display controller 618 can be configured to generate read memoryoperations to read the data representing the frame/video sequence from amemory (not shown) through a memory controller (not shown), for example.The display controller 618 can be configured to perform variousprocessing on the image data (e.g., still images, video sequences,etc.). In some examples, the display controller 618 can be configured toscale still images and to dither, scale and/or perform color spaceconversion on the frames of a video sequence. The display controller 618can be configured to blend the still image frames and the video sequenceframes to produce output frames for display. The display controller 618can also be more generally referred to as a display pipe, displaycontrol unit, or display pipeline. The display control unit can begenerally any hardware and/or firmware configured to prepare a frame fordisplay from one or more sources (e.g., still images and/or videosequences). More particularly, the display controller 618 can beconfigured to retrieve source frames from one or more source buffersstored in memory, composite frames from the source buffers, and displaythe resulting frames on the display 604. Accordingly, display controller618 can be configured to read one or more source buffers and compositethe image data to generate the output frame.

In some examples, the display controller and host processor can beintegrated into an ASIC, though in other examples, the host processor616 and display controller 618 can be separate circuits coupledtogether. The display controller 618 can provide various control anddata signals to the display, including timing signals (e.g., one or moreclock signals) and/or vertical blanking period and horizontal blankinginterval controls. The timing signals can include a pixel clock that canindicate transmission of a pixel. The data signals can include colorsignals (e.g., red, green, blue). The display controller 618 can controlthe display 604 in real-time, providing the data indicating the pixelsto be displayed as the display is displaying the image indicated by theframe. The interface to such a display 604 can be, for example, a videographics array (VGA) interface, a high definition multimedia interface(HDMI), a digital video interface (DVI), a LCD interface, a plasmainterface, or any other suitable interface.

Note that one or more of the functions described above can be performedby firmware stored in memory and executed by the touch processor intouch controller 612, or stored in program storage and executed by hostprocessor 616. The firmware can also be stored and/or transported withinany non-transitory computer-readable storage medium for use by or inconnection with an instruction execution system, apparatus, or device,such as a computer-based system, processor-containing system, or othersystem that can fetch the instructions from the instruction executionsystem, apparatus, or device and execute the instructions. In thecontext of this document, a “non-transitory computer-readable storagemedium” can be any medium (excluding a signal) that can contain or storethe program for use by or in connection with the instruction executionsystem, apparatus, or device. The non-transitory computer readablemedium storage can include, but is not limited to, an electronic,magnetic, optical, electromagnetic, infrared, or semiconductor system,apparatus or device, a portable computer diskette (magnetic), a randomaccess memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), anerasable programmable read-only memory (EPROM) (magnetic), a portableoptical disc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flashmemory such as compact flash cards, secured digital cards, USB memorydevices, memory sticks, and the like.

The firmware can also be propagated within any transport medium for useby or in connection with an instruction execution system, apparatus, ordevice, such as a computer-based system, processor-containing system, orother system that can fetch the instructions from the instructionexecution system, apparatus, or device and execute the instructions. Inthe context of this document, a “transport medium” can be any mediumthat can communicate, propagate or transport the program for use by orin connection with the instruction execution system, apparatus, ordevice. The transport readable medium can include, but is not limitedto, an electronic, magnetic, optical, electromagnetic or infrared wiredor wireless propagation medium.

It is to be understood that the computing system 600 is not limited tothe components and configuration of FIG. 6, but can include other oradditional components in multiple configurations according to variousexamples. Additionally, the components of computing system 600 can beincluded within a single device, or can be distributed between multipledevices.

Therefore, according to the above, some examples of the disclosure aredirected to an electronic device comprising: a lower surface; an uppersurface; and a force sensing sealing structure situated between thelower surface and the upper surface, wherein the force sensing sealingstructure comprises: a flexible cover material formed in a connectedcircumferential shape, the cover material enclosing a dielectric; afirst conductive plate embedded in a first location of the covermaterial; and a second conductive plate embedded in a second location ofthe cover material; sense circuitry operatively coupled to the firstconductive plate, the sense circuitry configured to sense a capacitancebetween the first conductive plate and the second conductive plate; anda processor configured to determine a magnitude of an applied force atthe upper surface of the device based on the sensed capacitance.Additionally or alternatively, in some examples the second location isopposite of the first location; and the first conductive plate and thesecond conductive plate are horizontal with respect to the force sensingsealing structure. Additionally or alternatively, in some examples, theelectronic device further comprises drive circuitry coupled to thesecond conductive plate, the drive circuitry configured to apply a drivesignal to the second conductive plate. Additionally or alternatively, insome examples the first conductive plate and the second conductive plateare spaced a first distance from each other and have a first capacitancein the absence of the applied force; and the first conductive plate andthe second conductive plate are spaced a second distance from each otherand have a second capacitance in response to the applied force.Additionally or alternatively, in some examples the first conductiveplate is one of a plurality of first conductive plates; the secondconductive plate is one of a plurality of second conductive plates; andeach first conductive plate corresponds to a second conductive plate asa pair of conductive plates, each pair of conductive plates at a uniquelocation of the force sensing sealing structure. Additionally oralternatively, in some examples the processor is further configured to:sense a capacitance of each pair of conductive plates and determine alocation of the applied force based on the sensed capacitances.Additionally or alternatively, in some examples the electronic devicefurther comprises a touch screen configured for sensing a location oftouch, wherein the processor is further configured to determine alocation of the applied force based on the location of touch.Additionally or alternatively, in some examples an exterior of theflexible cover material is in direct contact with the lower surface andthe upper surface. Additionally or alternatively, in some examples thelower surface or the upper surface comprises a channel and the forcesensing sealing structure is situated in the channel. Additionally oralternatively, in some examples the upper surface comprises a covermaterial of the device.

Some examples of the disclosure relate to a force sensing sealingstructure comprising: a flexible cover material formed in a connectedcircumferential shape, the cover material enclosing a dielectric; afirst conductive plate embedded in a first location of the covermaterial; and a second conductive plate embedded in a second location ofthe cover material, wherein: the first conductive plate is operativelycoupled to sense circuitry configured to sense a capacitance between thefirst conductive plate and the second conductive plate, the capacitanceindicative of an applied force at the force sensing sealing structure.Additionally or alternatively, in some examples the dielectric is anon-structural compressible dielectric. Additionally or alternatively,in some examples the dielectric is air or silicone. Additionally oralternatively, in some examples the second location is opposite of thefirst location. Additionally or alternatively, in some examples thefirst conductive plate and the second conductive plate are horizontalwith respect to the force sensing sealing structure. Additionally oralternatively, in some examples the second conductive plate isoperatively coupled to drive circuitry, the drive circuitry configuredto apply a drive signal to the second conductive plate. Additionally oralternatively, in some examples the first conductive plate and thesecond conductive plate are spaced a first distance from each other andhave a first capacitance in the absence of the applied force; and thefirst conductive plate and the second conductive plate are spaced asecond distance from each other and have a second capacitance inresponse to the applied force. Additionally or alternatively, in someexamples the first conductive plate is one of a plurality of firstconductive plates; the second conductive plate is one of a plurality ofsecond conductive plates; and each first conductive plate corresponds toa second conductive plate as a pair of conductive plates, each pair ofconductive plates at a unique location of the force sensing sealingstructure. Additionally or alternatively, in some examples the firstconnection is one of a plurality of first connections; the secondconnection is one of a plurality of second connections; each firstconductive plate is coupled to a first connection of the plurality offirst connections; each second conductive plate is coupled to a secondconnection of the plurality of second connections.

Some examples of the disclosure relate to an electronic devicecomprising: a lower surface; an upper surface; and a force sensingsealing structure comprising: means for compressing under an appliedforce at the upper surface; and means for sensing a capacitance of theforce sensing sealing structure, the capacitance indicative of theapplied force at the upper surface, wherein the force sensing sealingstructure is situated between the first surface and the second surface.

Although examples of this disclosure have been fully described withreference to the accompanying drawings, it is to be noted that variouschanges and modifications will become apparent to those skilled in theart. Such changes and modifications are to be understood as beingincluded within the scope of examples of this disclosure as defined bythe appended claims.

What is claimed is:
 1. An electronic device comprising: a lower surface;an upper surface, the upper surface comprising a cover material that isparallel to a cover material plane; and a force sensing sealingstructure situated between the lower surface and the upper surface;sense circuitry operatively coupled to the force sensing sealingstructure, the sense circuitry configured to sense a capacitance of theforce sensing sealing structure; and a processor configured to determinea magnitude of an applied force at the upper surface of the device basedon the sensed capacitance, wherein: the lower surface comprises achannel and the force sensing sealing structure is situated in thechannel, the channel comprises a first channel surface and a secondchannel surface, the first channel surface and the second channelsurface parallel to each other and perpendicular to the upper surfaceand the lower surface, the first channel surface is at a location in thecover material plane that overlaps the cover material, and the secondchannel surface is at a location in the cover material plane that doesnot overlap the cover material.
 2. The electronic device of claim 1,wherein: the channel comprises an inner channel surface and an outerchannel surface in contact with the force sensing sealing structure, andthe inner channel surface comprises a gap, wherein the force sensingsealing structure is not in contact with the inner channel surface at alocation of the gap.
 3. The electronic device of claim 2, furthercomprising: a routing trace that couples the force sensing sealingstructure to the sense circuitry, wherein the routing trace is disposedwithin the gap of the inner channel surface.
 4. The electronic device ofclaim 1, wherein: the first channel surface is positioned around anouter perimeter of the force sensing sealing structure, and the forcesensing sealing structure is positioned around the second channelsurface.
 5. The electronic device of claim 1, further comprising: aclamp in contact with the lower surface and the upper surface, the clampconfigured to apply a nominal force to the upper surface and the lowersurface to hold the upper surface and lower surface together around theforce sensing sealing structure.
 6. The electronic device of claim 5,wherein the clamp further comprises a spring that applies the nominalforce to the upper surface and the lower surface.
 7. The electronicdevice of claim 5, wherein the clamp is located inside of the electronicdevice.
 8. The electronic device of claim 1, wherein the force sensingsealing structure comprises: a flexible sensor cover material formed ina connected circumferential shape, the sensor cover material enclosing adielectric; a first conductive plate embedded in a first location of thesensor cover material; and a second conductive plate embedded in asecond location of the sensor cover material.
 9. The electronic deviceof claim 8, wherein: the sense circuitry is coupled to the firstconductive plate of the force sensing sealing structure, and thecapacitance of the force sensing sealing structure is a capacitancebetween the first conductive plate and the second conductive plate. 10.An electronic device comprising: a lower surface; an upper surface, theupper surface comprising a cover material that is parallel to a covermaterial plane; and a force sensing sealing structure comprising: ameans for compressing under an applied force at the upper surface; and ameans for sensing a capacitance of the force sensing sealing structure,the capacitance indicative of the applied force at the upper surface,wherein: the force sensing sealing structure is situated between theupper surface and the lower surface, and the lower surface comprises achannel and the force sensing sealing structure is situated in thechannel, the channel comprises a first channel surface and a secondchannel surface, the first channel surface and the second channelsurface parallel to each other and perpendicular to the upper surfaceand the lower surface, the first channel surface is at a location in thecover material plane that overlaps the cover material, and the secondchannel surface is at a location in the cover material plane that doesnot overlap the cover material.
 11. The electronic device of claim 10,wherein: the channel comprises an inner channel surface and an outerchannel surface in contact with the force sensing sealing structure, andthe inner channel surface comprises a gap, wherein the force sensingsealing structure is not in contact with the inner channel surface at alocation of the gap.
 12. The electronic device of claim 11, furthercomprising: sense circuitry operatively coupled to the force sensingsealing structure, the sense circuitry configured to sense a capacitanceof the force sensing sealing structure; and a routing trace that couplesthe force sensing sealing structure to the sense circuitry, wherein therouting trace is disposed within the gap of the inner channel surface.13. The electronic device of claim 10, wherein: the first channelsurface is positioned around an outer perimeter of the force sensingsealing structure, and the force sensing sealing structure is positionedaround the second channel surface.
 14. The electronic device of claim10, further comprising: a clamp in contact with the lower surface andthe upper surface, the clamp configured to apply a nominal force to theupper surface and the lower surface to hold the upper surface and lowersurface together around the force sensing sealing structure.
 15. Theelectronic device of claim 14, wherein the clamp further comprises aspring that applies the nominal force to the upper surface and the lowersurface.
 16. The electronic device of claim 14, wherein the clamp islocated inside of the electronic device.
 17. The electronic device ofclaim 10, wherein the means for compressing under an applied force atthe upper surface comprises a flexible sensor cover material formed in aconnected circumferential shape, the sensor cover material enclosing adielectric.
 18. The electronic device of claim 17, wherein the means forsensing a capacitance of the force sensing sealing structure comprises:a first conductive plate embedded in a first location of the covermaterial; and a second conductive plate embedded in a second location ofthe cover material.